为什么通过Spring加载log4j2.xml会为log4j1类抛出NoClassDefFoundError？

我正在向Tomcat 8部署Spring 4 Web应用程序，并尝试通过Spring加载log4j配置（ log4j2.xml ），以便它可以存储在WAR之外 . 有了这个配置，Spring会在部署期间为log4j1类（ org.apache.log4j.xml.DOMConfigurator ）抛出 NoClassDefFoundError . 但是如果Log4j2在类路径上，则会正确加载 . 我的依赖项中没有显式的logj1库，只有log4j2 .

Initializing Log4J with Spring?建议在web.xml中配置log4j . 我试过这个，但是根本没有加载log4j，也没有从应用程序打印日志语句 .

Correctly using Log4jConfigurer in Spring建议在Tomcat中配置自定义log4j配置文件名，但不是我想要的 . 给定文件名，我需要从WAR外部加载文件 .

Spring配置加载log4j2.xml：

<!-- Load Log4j config file via Spring -->
<bean id="log4jInitialization" class="org.springframework.beans.factory.config.MethodInvokingFactoryBean">
    <property name="targetClass" value="org.springframework.util.Log4jConfigurer"/>
    <property name="targetMethod" value="initLogging"/>
    <property name="arguments">
        <list>
            <value>${log4j.config.location}</value>
            <value>${log4j.refresh.interval}</value>
        </list>
    </property>
</bean>

完整堆栈跟踪：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'log4jInitialization' defined in ServletContext resource [/WEB-INF/spring/root-context.xml]: Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: org/apache/log4j/xml/DOMConfigurator
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1553)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:539)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:302)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:298)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:684)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:760)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:482)
    at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:403)
    at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:306)
    at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:106)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4760)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5184)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:724)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:700)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:714)
    at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:919)
    at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1704)
    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NoClassDefFoundError: org/apache/log4j/xml/DOMConfigurator
    at org.springframework.util.Log4jConfigurer.initLogging(Log4jConfigurer.java:102)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.springframework.util.MethodInvoker.invoke(MethodInvoker.java:269)
    at org.springframework.beans.factory.config.MethodInvokingBean.invokeWithTargetException(MethodInvokingBean.java:119)
    at org.springframework.beans.factory.config.MethodInvokingFactoryBean.afterPropertiesSet(MethodInvokingFactoryBean.java:106)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1612)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1549)